Ultrasonic doppler device

ABSTRACT

Portable self-contained ultrasonic doppler device including transmitting and receiving transducer means carried by a support structure, speaker means and electronic doppler circuitry connected to the transducer means and the speaker means, all mounted in a common housing. Attenuation means are provided between the housing and the speaker means and the support structure for attenuating transmission of audio frequency waves from the speaker to the transducer means and to minimize feedback effects.

United States Patent [191 Rosauer et al.

[ Apr. 17, 1973 ULTRASONIC DOPPLER DEVICE [54] 3,046,544 7/1962 Auer,Jr. et al ..340/8 S [75] lnventors: Peter J. Rosauer, Prospect; RichardPrimary ExammerR1chard A. Farley sukoskl Nonldge both ofAtt0rney-Alberts, Brezina & Lund [73] Assignee: Champion Spark PlugCompany,

Toledo, Ohio 57 ABSTRACT [22] Filed: 1971 Portable self-containedultrasonic doppler device in- 1 App] 114 525 cluding transmitting andreceiving transducer means carried by a support structure, speaker meansand electronic doppler circuitry connected to the trans- [52] US. Cl...340/1 R, 179/179, ducer means and the Speaker means an mounted in a[51] Int. Cl G018 9 /66 common housing. Attenuation means are provided[581 new of sun;111111iiiiiiiiiiiiiiii aayi'az 3 D 3 R eeeweee eheheeeiee eee ehe eeeekee meeee end we 340/5 A 5 T 8 R 8 S; 1 81/05 7support structure for attenuating transmission of audio 180 frequencywaves from the speaker to the transducer means and to minimize feedbackeffects. [56] References Cited 7 Claims, 4 Drawing Figures UNITED STATESPATENTS 3,123,798 3/1964 Holloway et al ...340/3 D 5 3 m 36 4| 35 4 523O 39 44 K r 32 46 I2 48 '7 I9 47 2| k I A \r PATENTEDAPMQ I 2 Y3.728.670

25 III AUDIO AMP INVENTORS PETER J. ROSAUER RICHARD c. suxosm BY m, WvM

ATTORNEYS ULTRASONIC DOPPLER DEVICE This invention relates to anultrasonic doppler device and more particularly to a portableself-contained doppler device for medical applications, designed forengagement with a living body to produce audible sound wavescorresponding to blood flow and other movements within the body.

Ultrasonic instruments have heretofore been provided for transmittingultrasonic energy into a body and receiving reflected energy which isfrequency-shifted, due to movement of a reflecting surface within thebody, according to the Doppler principle. In general, such instrumentshave included a probe unit connected by means of a cable to anindicating and energizing unit including a speaker. In operation, theprobe is placed against a body to be examined and the speaker produces awhishing sound in response to flowing blood or throbbing sounds inresponse to pulsations of blood vessels or movement of other interfaceswithin the body.

This invention was evolved with the general object of providing aportable self-contained device in which the ultrasonic transducer means,electronic circuitry and speaker are all mounted in a small portablehousing which may be held in the hand to contact the body and to producethe audible sounds.

An important aspect of the invention is in the discovery that inattempting to support the ultrasonic transducer means and the speakermeans on a common relatively small housing, feedback oscillations areproduced. This is contrary to what might be expected because theultrasonic waves are transmitted and received at relatively highfrequencies, on the order of 2.5 MHz, by way of example, whereas thespeaker produces vibrations in the audible range and it would not beexpected that any feedback problem would be encountered. It is found,however, that there is a serious feedback problem and although the exactreasons for the problem are not known with certainty, it has beenfurther found that by attenuating the transmission of audio frequencysounds from the speaker to the transducer means, the feedbackoscillations can be minimized.

In accordance with an important feature of the invention, the ultrasonictransducer means are carried by a support structure separate from thehousing and attenuation means are provided between the transducersupport structure and the housing. In a preferred embodiment, thetransducer support structure has an outwardly facing annular groove andan open end portion of the housing as an inwardly facing annular groovewith a damping member being seated in the outwardly facing annulargroove and extending into the inwardly facing annular groove. Mostpreferrably, the damping member is of medium density sponge rubber orthe equivalent and has a plurality of angularly spaced portionsextending into the inwardly facing annular groove of the open endportion of the housing.

Another important feature relates to the provision of attenuation meansbetween the speaker frame and the housing, which may most preferablycomprise rubber grommets or the like.

This invention contemplates other objects, features and advantages whichwill become fully apparent from the following detailed description takenin conjunction with the accompanying drawing which illustrates apreferred embodiment and in which:

FIG. 1 is a top plan view of a ultrasonic doppler device constructed inaccordance with the principles of this invention;

FIG. 2 is a cross-sectional view taken substantially along line IIII ofFIG. 1;

FIG. 3 is a cross-sectional view taken substantially along line III-IIIof FIG. 2; and

FIG. 4 is a schematic electrical diagram.

Reference numeral generally designates an ultrasonic doppler deviceconstructed in accordance with the principles of this invention. Ingeneral, the device 10 comprises a housing 11, a transducer support 12at one end of the housing iii, a speaker 13 supported within the housing11 and electronic circuitry 14 which may be supported on a circuit board15 in the housing 11. Batteries 16 are disposed within the housing 11for energizing the electronic circuitry.

A transmitting transducer 17 and a receiving transducer 18 are mountedon the back faces of wedge blocks 19 and 20 which are secured within acavity in the end face of the support structure 12. Preferably, thewedge blocks 19 an 20 are acoustically isolated by a layer 21 ofattenuating material which may include an epoxy material and which mayserve to secure the wedge blocks 19 and 20 together.

In oppration, the outer faces of the wedge blocks 19 and 20 are engagedwith the skin of a patient, preferably with a thin layer of a couplingjelly on the surfaces of the blocks 19 and 20 to efficiently coupleultrasonic waves.

As shown in FIG. 4, the transmitting transducer 17 is energized from aRF. oscillator 23 which may be operative at 2.5 MHz, by way of example.The receiving transducer 18 is connected to the input of an amplifier 24having an output connected to a detector 25 which functions to produceaudio frequency signals in response to frequency-shifted components ofthe received signals, such audio frequency signals being amplified by anaudio amplifier 26 and being applied to the speaker 13.

When, for example, the unit is placed in proximity to an artery, acharacteristic whishing sound is produced in response to the flowingblood. Also, throbbing sounds may be produced in response to movementsof the walls of blood vessels or in response to movements of otherinterfaces such as from the heart, for example.

In accordance with an important feature of the invention, the supportstructure, 12 has an inner end portion 29 disposed within an open endportion 30 of the housing 11, such portions respectively being formedwith an outwardly facing annular groove 31 and an inwardly facingannular groove 32. A damping member 33 is disposed in the groove 31 andextends into the groove 32. Preferably, the damping member may beformedto provide a plurality of angularly spaced portions 33a, 33b, 33c and33d projecting radially outwardly into the groove 32, as shown in FIG.3. The member 33 is preferably of a medium density sponge rubber or theequivalent. The clamping member 33 forms attenuation means whichminimizes transmission of audio frequency waves from the housing 11 tothe transducer support structure 12 and minimizes feedback effects.

Another important feature is in the provision of attenuation means inthe support of the speaker 13 from the housing 11. The illustratedspeaker 13 has a conventional frame 35, having a peripheral flange 36.The speaker 35 also includes a conventional cone or diaphragm theperiphery of which is supported from the frame 35 and having a coneconnected to the central portion thereof and movable in a magnetic airgap, a magnet 37 being supported on the central part of the frame 35.

For support of the speaker 35, screws 39 and 40 extend through holes ina top wall 41 of the housing thence through a pair of rubber grommets 43and 44, thence through holes in the peripheral flange 36 of the speakerframe 35, thence through another pair of grommets 45 and 46 and thenceinto the upper ends of a pair of support posts 47 and 48 which extendupwardly from a lower wall 49 of the housing and which may preferably beintegral therewith. The grommets 43-46 serve as attenuation means tominimize transmission of audio frequency waves from the speaker frame tothe housing 1 l, to further minimize the transmission of the waves tothe transducer support structure l2 and to further minimize feedbackeffects.

It is noted that the top wall 41 and the bottom wall 49 are separate andthe screws 39 and 40 serve the additional function of securing the sametogether. For access to the battery compartment, the lower wall of thehousing may be in two parts, the part 49 which underlies the speaker 13and the circuitry 14 and a part 50 which underlies the batteries 16.Part 50 of the bottom wall is secured by a screw 51 to one end of a post52, the opposite end of post 52 being secured to the top wall 41 by ascrew 53. Thus, by removal of the screw 51, the bottom wall part 50 maybe removed, for access to the battery compartment. Also, it permitsaccess to the damping member 33 for inspection and cleaning orreplacement thereof. In tyis connection, it is importantthat there be noconnection from the support structure 12 to the housing 11 other thanthrough the damping member 33 and it is particularly important thatthere be no fluid therebetween, which would cause transmission of theaudio frequency waves.

It will be understood that modifications and variations may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

We claim as our invention:

1. In an ultrasonic doppler device, transmitting and receivingtransducer means for transmitting ultrasonic energy at a hightransmission frequency into a body and for producing received signals athigh frequencies shifted from said high transmission frequency inresponse to reflections from moving interfaces within said body,transmitting and receiving circuitry for energizing said transducermeans and for amplifying said frequency-shifted received signals,detector circuitry responsive to said amplified received signals toproduce a low frequency signal in the audible frequency range, speakermeans responsive to said audio frequency signal to develop correspondingaudio frequency compressional waves, compact housing means of a solidmaterial enclosing said transmitting and receiving circuitry and saiddetector circuitry and adapted to be held in one hand for positioningsaid transducer means against a body, a support structure for saidtransmitting and receiving transducer means, first support meanssupporting said support structure from said housing means, and secondsupport means su porting said speaker means in said housing means, aleast one of said first and second support means including attenuationmeans for attenuating transmission of said audio frequency compressionalwaves from said speaker means through said solid material of saidhousing means to said support structure to prevent movement of saidtransducer means in response to said audio frequency compressionalwaves.

2. In a device as defined in claim 1, said attenuation means includingfirst attenuation means in said first support means and secondattenuation means in said second support means, said second attenuationmeans being arranged to highly attenuate transmission of said audiofrequency compressional waves from said speaker means to said solidmaterial of said housing means and said first attenuation means beingarranged to highly attenuate the transmission of any remainingcompression waves from said solid material to said transducer means.

3. In a device as defined in claim 1, said housing means having an openend portion, said support structure including an inner portion disposedwithin said open end portion of said housing means, and said attenuationmeans including a damping member disposed between the outer surface ofsaid inner portion of said support structure and an inner surface ofsaid open end portion of said housing means.

4. In a device as defined in claim 3, said outer surface of said innerportion of said support structure having an outwardly facing annulargroove therein, and said inner surface of said open end portion of saidhousing means having an inwardly facing annular groove therein, saidclamping member being seated in said outwardly facing annular groove andextending into said inwardly facingannular groove.

5. In a device as defined in claim 4, said damping member having aplurality of angularly spaced radially extending portions extending intosaid inwardly facing annular groove.

6. In a device as defined in claim 1, said attenuation means including amember of medium density sponge rubber or the equivalent.

7. In a device as defined in claim 1, said speaker including a framehaving a peripheral flange portion, and said attenuation means includingrubber grommet means supporting said annular flange portion of saidspeaker frame from said housing means.

l I 4K

1. In an ultrasonic doppler device, transmitting and receivingtransducer means for transmitting ultrasonic energy at a hightransmission frequency into a body and for producing received signals athigh frequencies shifted from said high transmission frequency inresponse to reflections from moving interfaces within said body,transmitting and receiving circuitry for energizing said transducermeans and for amplifying said frequency-shifted received signals,detector circuitry responsive to said amplified received signals toproduce a low frequency signal in the audible frequency range, speakermeans responsive to said audio frequency signal to develop correspondingaudio frequency compressional waves, compact housing means of a solidmaterial enclosing said transmitting and receiving circuitry and saiddetector circuitry and adapted to be held in one hand for positioningsaid transducer means against a body, a support structure for saidtransmitting and receiving transducer means, first support meanssupporting said support structure from said housing means, and secondsupport means supporting said speaker means in said housing means, atleast one of said first and second support means including attenuationmeans for attenuating transmission of said audio frequency compressionalwaves from said speaker means through said solid material of saidhousing means to said support structure to prevent movement of saidtransducer means in response to said audio frequency compressionalwaves.
 2. In a device as defined in claim 1, said attenuation meansincluding first attenuation means in said first support means and secondattenuation means in said second support means, said second attenuationmeans being arranged to highly attenuate transmission of said audiofrequency compressional waves from said speaker means to said solidmaterial of said housing means and said first attenuation means beingarranged to highly attenuate the transmission of any remainingcompression waves from said solid material to said transducer means. 3.In a device as defined in claim 1, said housing mEans having an open endportion, said support structure including an inner portion disposedwithin said open end portion of said housing means, and said attenuationmeans including a damping member disposed between the outer surface ofsaid inner portion of said support structure and an inner surface ofsaid open end portion of said housing means.
 4. In a device as definedin claim 3, said outer surface of said inner portion of said supportstructure having an outwardly facing annular groove therein, and saidinner surface of said open end portion of said housing means having aninwardly facing annular groove therein, said damping member being seatedin said outwardly facing annular groove and extending into said inwardlyfacing annular groove.
 5. In a device as defined in claim 4, saiddamping member having a plurality of angularly spaced radially extendingportions extending into said inwardly facing annular groove.
 6. In adevice as defined in claim 1, said attenuation means including a memberof medium density sponge rubber or the equivalent.
 7. In a device asdefined in claim 1, said speaker including a frame having a peripheralflange portion, and said attenuation means including rubber grommetmeans supporting said annular flange portion of said speaker frame fromsaid housing means.